/Engine/Plugins/FX/Niagara/Source/NiagaraEditor/Public/NiagaraParameterMapHistory.h
Record that a pin reads from the parameter map. The pin name is expected to be the namespaced parameter map version of the name. If any aliases are in place, they are removed.
int32 HandleVariableRead ( int32 ParameterMapIndex, const [FPin](API\Plugins\NiagaraEditor\TNiagaraParameterMapHistoryBuild-\FPin) * InPin, bool RegisterReadsAsVariables, const [FInputPin](API\Plugins\NiagaraEditor\TNiagaraParameterMapHistoryBuild-\FInputPin) * InDefaultPin, bool bFilterForCompilation, bool & OutUsedDefault )